/*
 * Copyright 2009 Jesse McLaughlin (nzjess@gmail.com)
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *         http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.travelfusion.xmlclient.handler.xmltool;

import java.io.InputStream;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.travelfusion.xmlclient.util.ResourceLoader;
import org.travelfusion.xmlclient.util.TfXSPIUtil;

import com.google.inject.Inject;
import com.google.inject.Singleton;
import com.mycila.xmltool.XMLDoc;
import com.mycila.xmltool.XMLTag;

/**
 * @author Jesse McLaughlin (nzjess@gmail.com)
 */
@Singleton
public class XmlToolTemplateCache {

  protected Map<Class<?>, XMLTag> templates = new ConcurrentHashMap<Class<?>, XMLTag>();

  protected ResourceLoader resourceLoader;

  @Inject(optional = true)
  public void setResourceLoader(ResourceLoader resourceLoader) {
    this.resourceLoader = resourceLoader;
  }

  public XMLTag getTemplate(Class<?> handlerType, Class<?> requestType) {
    XMLTag template = templates.get(requestType);
    if (template == null) {
      template = loadTemplate(handlerType, requestType);
      templates.put(requestType, template);
    }
    return template.duplicate();
  }

  protected XMLTag loadTemplate(Class<?> handlerType, Class<?> requestType) {
    InputStream stream = loadTemplateResourceAsStream(handlerType, requestType);
    return XMLDoc.from(stream, true);
  }

  protected InputStream loadTemplateResourceAsStream(Class<?> handlerType, Class<?> requestType) {
    if (resourceLoader != null) {
      return resourceLoader.loadTemplateResourceAsStream(handlerType, requestType);
    }
    else {
      return TfXSPIUtil.loadTemplateResourceAsStream(handlerType, requestType);
    }
  }
}
